The woman, Kim Suozzi, had terminal brain cancer, and wanted to
preserve her brain with the hope that it could one day be
revived.

Suozzi isn't alone, either. More than 100
people have undergone cryonics (freezing their body for
reviving later) or neuropreservation (freezing of just the head
and brain) since the first case in the 1960s, according to the
Alcor Life Extension Foundation, which performs both procedures.

Medical professionals and researchers have gotten quite good at
freezing and reviving human parts — everything from organs for
transplantation to
embryos and eggs for reproduction. But the human brain is a
whole other story.

The truth is, no one has ever been revived after death and
freezing. Experts, including Winfried Denk, a brain mapping expert
at the Max Planck Institute of Neurobiology in Germany, who
Harmon quoted in her story, think the ability to revive someone
who has undergone cryopreservation is at least 40 years away. By
then, hopefully, we'd also have developed cures to whatever
killed the patient in the first place.

The problem is, when the body dies, cells immediately start
releasing toxic substances and decomposing. It's extremely
difficult to prevent this natural process from happening, but a
few organizations, including Alcor, which Suozzi used, are giving
cryonics a try with the hope that one day they will be able to
bring their frozen patients back to life.

These
tanks hold cryopreserved remains of 49 individuals at Alcor Life
Extension Foundation’s headquarters in Scottsdale, Arizona. The
smaller tanks in the back contain just heads.STR New/Reuters

Within minutes of the patient's heart stopping and being
medically pronounced dead, the cryonics team places him/her in an
ice water bath to start the cooling and preservation process.

Life support is administered to artificially keep the heart
beating, the blood pumping, and to increase blood oxygen levels
to those experienced in airplanes. This keeps the brain healthy
during the cryopreservation process.

An external heart-lung machine takes over for the patient's
organs, and the patient is cooled to a temperature a few degrees
above the freezing point of water, where oxygen is no longer
necessary.

Blood is replaced with a cryoprotectant antifreeze solution
over the course of a few hours. The cryoprotectant chemicals used
are similar to those used for transporting organs for transplant.
This antifreeze
is crucial for keeping ice crystals from forming, since ice
expands and can form spiky crystals that damage brain cells.

The patient is slowly cooled (in a few more hours) via
nitrogen gas circulation to -193 degrees Fahrenheit. At this
temperature, their cells vitrify, and turn into a solid. They
technically
don't "freeze" since the process is ice-free, and molecules
instead move slower and slower until all chemistry stops.

Over the next two weeks, the patient is cooled to about -320
degrees Fahrenheit, and the cryopreserved brain and/or body is
stored under liquid nitrogen for long term care.

But how would freezing a brain work to bring a human back to
life? We really don't know yet.

Billions of cells make up the human brain, and the most important
thing in preserving it is keeping their connections intact. If
those connections are frozen intact, the hope is that future
scientists would be able to read them from a frozen brain and
recreate that person from those connections — either implanted
into a synthetic, or "lab-grown," brain and body, or potentially
into a computer.

What's hard is that researchers aren't even sure they fully
understand how these connections work to create memories and
personality. The Human Connectome
Project aims to learn more about this network, but
significant progress will take decades and hundreds of millions
of dollars.

While people are having their heads and bodies preserved now, it
will take a long time before they can be revived. What that will
look like, however, is a whole other story.